Email marketing uses email to communicate with subscribers and customers in order to nurture relationships and drive actions. At its foundation is the email list, a collection of addresses of people who have opted in, meaning they have given explicit consent to receive marketing communications. Opt-ins can be single (subscription confirmed at sign-up) or double opt-in (requiring a second confirmation step, such as clicking a link in a confirmation email). Common email formats include the email newsletter, a recurring email sharing updates, content, or offers, and the drip campaign, an automated series of emails sent based on time intervals or user actions.
Email performance is measured through several metrics. Open rate is the percentage of delivered emails that were opened, click rate is the percentage of delivered emails that received at least one click, and click-to-open rate (CTOR) measures the percentage of opens that resulted in a click, calculated as Unique Clicks divided by Unique Opens multiplied by 100. To make messaging more relevant, marketers use list segmentation, dividing the email list into groups based on characteristics or behavior. A nurture track based on behavior sends different messages depending on how users interact with previous emails or content, and progressive profiling gradually collects more information about a lead over time rather than asking for everything up front.
Email deliverability, the ability of an email to successfully reach the recipient's inbox, depends on sender reputation, which is how email providers perceive the trustworthiness of a sender based on history and behavior. Three technical standards, SPF, DKIM, and DMARC, are email authentication methods that verify senders and reduce spoofing. High spam complaint rates (the percentage of delivered emails that recipients mark as spam) hurt sender reputation, which is why every email should include an unsubscribe link, both for legal compliance and to maintain list health. List hygiene and list pruning involve regularly cleaning and updating an email list to remove inactive or invalid addresses, and re-engagement campaigns aim to reactivate dormant subscribers. Burnout occurs when subscribers become less responsive due to over-emailing or irrelevant content, and lead capture forms should ask only for essential information to reduce friction. Multi-step forms break questions into multiple pages to lower perceived effort.
Email also supports specific commercial tactics. Cart abandonment emails are automated follow-ups to users who added items to their cart but left without completing checkout. Lead magnets, valuable free offers like ebooks or checklists, are exchanged for a user's contact information, often through a lead magnet landing page or a squeeze page focused almost entirely on capturing an email. A thank-you page confirms a completed action and often presents next steps, upsells, or additional content. Nurture emails with soft CTAs focus on value and education with low-friction calls to action like reading a blog post, while hard CTAs ask directly for a high-commitment action such as starting a free trial or scheduling a demo.